The present invention relates to a method for preparing optically active substances and, more particularly, to a method for preparing halohydrin-containing esters or arboxylic acids with high optical purity by efficient symmetric hydrolysis of halohydrin-containing esters with specific microbes.
Optically active halohydrins are useful as starting materials for ferroelectric liquid crystals, pharmaceuticals and pesticides, and techniques for preparing halohydrins having optically high purity with improved efficiency are in demand. However, never until now is there any report on methods for making optically active monocarboxylic acid containing halohydrins or their esters with microbes. Heretofore, it has been reported to produce L-threochloromalic acid from chlorofumaric acid with fumarase as one method for producing optically active dicarboxylic acids containing halohydrins or their esters. However, this method is disadvantageous in that the starting materials are not only expensive but also substantially difficult to obtain. Besides, some reports are found in Mem. Fac. Sci. Kyushu Univ., Ser. C., 11(2), 217-224 (1974); Tetrahedron 36(1), 87-90 (1980); and J. Am. Chem. Soc. 110, 7538-7539 (1988), but they all have a disadvantage of using expensive starting materials and other defects.
The present inventors have thus made intensive and extensive studies of the preparation of optically active substances containing halohydrins and, in consequence, have found that they can efficiently be prepared by the asymmetric hydrolysis of halohydrin-containing esters with a specific microbe.